gtkdnd.c

gtk是linux一款强大的夸平台的图形化开发工具

    {
      GdkModifierType state = 0;
      
      switch (event->type)
	{
	case GDK_MOTION_NOTIFY:
	  state = event->motion.state;
	  break;
	case GDK_BUTTON_PRESS:
	case GDK_2BUTTON_PRESS:
	case GDK_3BUTTON_PRESS:
	case GDK_BUTTON_RELEASE:
	  state = event->button.state;
	  break;
	case GDK_KEY_PRESS:
	case GDK_KEY_RELEASE:
	  state = event->key.state;
	  break;
	case GDK_ENTER_NOTIFY:
	case GDK_LEAVE_NOTIFY:
	  state = event->crossing.state;
	  break;
	default:
	  break;
	}
      
      if ((button == 2 || button == 3) && (actions & GDK_ACTION_ASK))
	{
	  *suggested_action = GDK_ACTION_ASK;
	  *possible_actions = actions;
	}
      else if (state & (GDK_SHIFT_MASK | GDK_CONTROL_MASK))
	{
	  if ((state & GDK_SHIFT_MASK) && (state & GDK_CONTROL_MASK))
	    {
	      if (actions & GDK_ACTION_LINK)
		{
		  *suggested_action = GDK_ACTION_LINK;
		  *possible_actions = GDK_ACTION_LINK;
		}
	    }
	  else if (state & GDK_CONTROL_MASK)
	    {
	      if (actions & GDK_ACTION_COPY)
		{
		  *suggested_action = GDK_ACTION_COPY;
		  *possible_actions = GDK_ACTION_COPY;
		}
	      return;
	    }
	  else
	    {
	      if (actions & GDK_ACTION_MOVE)
		{
		  *suggested_action = GDK_ACTION_MOVE;
		  *possible_actions = GDK_ACTION_MOVE;
		}
	      return;
	    }
	}
      else
	{
	  *possible_actions = actions;

	  if ((state & (GDK_MOD1_MASK)) && (actions & GDK_ACTION_ASK))
	    *suggested_action = GDK_ACTION_ASK;
	  else if (actions & GDK_ACTION_COPY)
	    *suggested_action =  GDK_ACTION_COPY;
	  else if (actions & GDK_ACTION_MOVE)
	    *suggested_action = GDK_ACTION_MOVE;
	  else if (actions & GDK_ACTION_LINK)
	    *suggested_action = GDK_ACTION_LINK;
	}
    }
  
  return;
}

static GdkCursor *
gtk_drag_get_cursor (GdkDragAction action)
{
  gint i;
  
  for (i = 0 ; i < n_drag_cursors - 1; i++)
    if (drag_cursors[i].action == action)
      break;

  if (drag_cursors[i].cursor == NULL)
    {
      GdkColor fg, bg;

      GdkPixmap *pixmap = 
	gdk_bitmap_create_from_data (NULL, 
				     drag_cursors[i].bits,
				     CURSOR_WIDTH, CURSOR_HEIGHT);
      GdkPixmap *mask = 
	gdk_bitmap_create_from_data (NULL, 
				     drag_cursors[i].mask,
				     CURSOR_WIDTH, CURSOR_HEIGHT);

      gdk_color_white (gdk_colormap_get_system (), &bg);
      gdk_color_black (gdk_colormap_get_system (), &fg);
      
      drag_cursors[i].cursor = gdk_cursor_new_from_pixmap (pixmap, mask, &fg, &bg, 0, 0);

      gdk_pixmap_unref (pixmap);
      gdk_pixmap_unref (mask);
    }

  return drag_cursors[i].cursor;
}

/********************
 * Destination side *
 ********************/

/*************************************************************
 * gtk_drag_get_data:
 *     Get the data for a drag or drop
 *   arguments:
 *     context - drag context
 *     target  - format to retrieve the data in.
 *     time    - timestamp of triggering event.
 *     
 *   results:
 *************************************************************/

void 
gtk_drag_get_data (GtkWidget      *widget,
		   GdkDragContext *context,
		   GdkAtom         target,
		   guint32         time)
{
  GtkWidget *selection_widget;

  g_return_if_fail (widget != NULL);
  g_return_if_fail (context != NULL);

  selection_widget = gtk_drag_get_ipc_widget ();

  gdk_drag_context_ref (context);
  gtk_widget_ref (widget);
  
  gtk_signal_connect (GTK_OBJECT (selection_widget), "selection_received",
		      GTK_SIGNAL_FUNC (gtk_drag_selection_received), widget);

  gtk_object_set_data (GTK_OBJECT (selection_widget), "drag-context", context);

  gtk_selection_convert (selection_widget,
			 gdk_drag_get_selection (context),
			 target,
			 time);
}


/*************************************************************
 * gtk_drag_get_source_widget:
 *     Get the widget the was the source of this drag, if
 *     the drag originated from this application.
 *   arguments:
 *     context: The drag context for this drag
 *   results:
 *     The source widget, or NULL if the drag originated from
 *     a different application.
 *************************************************************/

GtkWidget *
gtk_drag_get_source_widget (GdkDragContext *context)
{
  GSList *tmp_list;

  tmp_list = source_widgets;
  while (tmp_list)
    {
      GtkWidget *ipc_widget = tmp_list->data;
      
      if (ipc_widget->window == context->source_window)
	{
	  GtkDragSourceInfo *info;
	  info = gtk_object_get_data (GTK_OBJECT (ipc_widget), "gtk-info");

	  return info ? info->widget : NULL;
	}

      tmp_list = tmp_list->next;
    }

  return NULL;
}

/*************************************************************
 * gtk_drag_finish:
 *     Notify the drag source that the transfer of data
 *     is complete.
 *   arguments:
 *     context: The drag context for this drag
 *     success: Was the data successfully transferred?
 *     time:    The timestamp to use when notifying the destination.
 *   results:
 *************************************************************/

void 
gtk_drag_finish (GdkDragContext *context,
		 gboolean        success,
		 gboolean        del,
		 guint32         time)
{
  GdkAtom target = GDK_NONE;

  g_return_if_fail (context != NULL);

  if (success && del)
    {
      target = gdk_atom_intern ("DELETE", FALSE);
    }
  else if (context->protocol == GDK_DRAG_PROTO_MOTIF)
    {
      target = gdk_atom_intern (success ? 
				  "XmTRANSFER_SUCCESS" : 
				  "XmTRANSFER_FAILURE",
				FALSE);
    }

  if (target != GDK_NONE)
    {
      GtkWidget *selection_widget = gtk_drag_get_ipc_widget ();

      gdk_drag_context_ref (context);
      
      gtk_object_set_data (GTK_OBJECT (selection_widget), "drag-context", context);
      gtk_signal_connect (GTK_OBJECT (selection_widget), "selection_received",
			  GTK_SIGNAL_FUNC (gtk_drag_selection_received),
			  NULL);
      
      gtk_selection_convert (selection_widget,
			     gdk_drag_get_selection (context),
			     target,
			     time);
    }
  
  if (!del)
    gdk_drop_finish (context, success, time);
}

/*************************************************************
 * gtk_drag_highlight_paint:
 *     Paint a highlight indicating drag status onto the widget.
 *   arguments:
 *     widget:
 *   results:
 *************************************************************/

static void 
gtk_drag_highlight_paint (GtkWidget  *widget)
{
  gint x, y, width, height;

  g_return_if_fail (widget != NULL);

  if (GTK_WIDGET_DRAWABLE (widget))
    {
      if (GTK_WIDGET_NO_WINDOW (widget))
	{
	  x = widget->allocation.x;
	  y = widget->allocation.y;
	  width = widget->allocation.width;
	  height = widget->allocation.height;
	}
      else
	{
	  x = 0;
	  y = 0;
	  gdk_window_get_size (widget->window, &width, &height);
	}
      
      gtk_draw_shadow (widget->style, widget->window,
		       GTK_STATE_NORMAL, GTK_SHADOW_OUT,
		       x, y, width, height);
      
      gdk_draw_rectangle (widget->window,
			  widget->style->black_gc,
			  FALSE,
			  x, y, width - 1, height - 1);
    }
}

/*************************************************************
 * gtk_drag_highlight_expose:
 *     Callback for expose_event for highlighted widgets.
 *   arguments:
 *     widget:
 *     event:
 *     data:
 *   results:
 *************************************************************/

static gboolean
gtk_drag_highlight_expose (GtkWidget      *widget,
			   GdkEventExpose *event,
			   gpointer        data)
{
  gtk_drag_highlight_paint (widget);
  return TRUE;
}

/*************************************************************
 * gtk_drag_highlight:
 *     Highlight the given widget in the default manner.
 *   arguments:
 *     widget:
 *   results:
 *************************************************************/

void 
gtk_drag_highlight (GtkWidget  *widget)
{
  gtk_signal_connect_after (GTK_OBJECT (widget), "draw",
			    GTK_SIGNAL_FUNC (gtk_drag_highlight_paint),
			    NULL);
  gtk_signal_connect (GTK_OBJECT (widget), "expose_event",
		      GTK_SIGNAL_FUNC (gtk_drag_highlight_expose),
		      NULL);

  gtk_widget_queue_draw (widget);
}

/*************************************************************
 * gtk_drag_unhighlight:
 *     Refresh the given widget to remove the highlight.
 *   arguments:
 *     widget:
 *   results:
 *************************************************************/

void 
gtk_drag_unhighlight (GtkWidget *widget)
{
  g_return_if_fail (widget != NULL);

  gtk_signal_disconnect_by_func (GTK_OBJECT (widget),
				 GTK_SIGNAL_FUNC (gtk_drag_highlight_paint),
				 NULL);
  gtk_signal_disconnect_by_func (GTK_OBJECT (widget),
				 GTK_SIGNAL_FUNC (gtk_drag_highlight_expose),
				 NULL);
  
  gtk_widget_queue_clear (widget);
}

/*************************************************************
 * gtk_drag_dest_set:
 *     Register a drop site, and possibly add default behaviors.
 *   arguments:
 *     widget:    
 *     flags:     Which types of default drag behavior to use
 *     targets:   Table of targets that can be accepted
 *     n_targets: Number of of entries in targets
 *     actions:   
 *   results:
 *************************************************************/

void 
gtk_drag_dest_set   (GtkWidget            *widget,
		     GtkDestDefaults       flags,
		     const GtkTargetEntry *targets,
		     gint                  n_targets,
		     GdkDragAction         actions)
{
  GtkDragDestSite *site;
  
  g_return_if_fail (widget != NULL);

  /* HACK, do this in the destroy */
  site = gtk_object_get_data (GTK_OBJECT (widget), "gtk-drag-dest");
  if (site)
    gtk_signal_disconnect_by_data (GTK_OBJECT (widget), site);

  if (GTK_WIDGET_REALIZED (widget))
    gtk_drag_dest_realized (widget);

  gtk_signal_connect (GTK_OBJECT (widget), "realize",
		      GTK_SIGNAL_FUNC (gtk_drag_dest_realized), NULL);

  site = g_new (GtkDragDestSite, 1);

  site->flags = flags;
  site->have_drag = FALSE;
  if (targets)
    site->target_list = gtk_target_list_new (targets, n_targets);
  else
    site->target_list = NULL;

  site->actions = actions;
  site->do_proxy = FALSE;

  gtk_object_set_data_full (GTK_OBJECT (widget), "gtk-drag-dest",
			    site, gtk_drag_dest_site_destroy);
}

/*************************************************************
 * gtk_drag_dest_set_proxy:
 *     Set up this widget to proxy drags elsewhere.
 *   arguments:
 *     widget:          
 *     proxy_window:    window to which forward drag events
 *     protocol:        Drag protocol which the dest widget accepts
 *     use_coordinates: If true, send the same coordinates to the
 *                      destination, because it is a embedded 
 *                      subwindow.
 *   results:
 *************************************************************/

void 
gtk_drag_dest_set_proxy (GtkWidget      *widget,
			 GdkWindow      *proxy_window,
			 GdkDragProtocol protocol,
			 gboolean        use_coordinates)
{
  GtkDragDestSite *site;
  
  g_return_if_fail (widget != NULL);

  /* HACK, do this in the destroy */
  site = gtk_object_get_data (GTK_OBJECT (widget), "gtk-drag-dest");
  if (site)
    gtk_signal_disconnect_by_data (GTK_OBJECT (widget), site);

  if (GTK_WIDGET_REALIZED (widget))
    gtk_drag_dest_realized (widget);

  gtk_signal_connect (GTK_OBJECT (widget), "realize",
		      GTK_SIGNAL_FUNC (gtk_drag_dest_realized), NULL);

  site = g_new (GtkDragDestSite, 1);

  site->flags = 0;
  site->have_drag = FALSE;
  site->target_list = NULL;
  site->actions = 0;
  site->proxy_window = proxy_window;
  if (proxy_window)
    gdk_window_ref (proxy_window);
  site->do_proxy = TRUE;
  site->proxy_protocol = protocol;
  site->proxy_coords = use_coordinates;

  gtk_object_set_data_full (GTK_OBJECT (widget), "gtk-drag-dest",
			    site, gtk_drag_dest_site_destroy);
}

/*************************************************************
 * gtk_drag_dest_unset
 *     Unregister this widget as a drag target.
 *   arguments:
 *     widget:
 *   results:
 *************************************************************/

void 
gtk_drag_dest_unset (GtkWidget *widget)
{
  g_return_if_fail (widget != NULL);

  gtk_object_set_data (GTK_OBJECT (widget), "gtk-drag-dest", NULL);
}

/*************************************************************
 * gtk_drag_dest_handle_event:
 *     Called from widget event handling code on Drag events
 *     for destinations.
 *
 *   arguments:
 *     toplevel: Toplevel widget that received the event
 *     event: